BRAKE ACCUMULATOR SERVICE TEST AND CHARGE
Lowering the Piston in Brake Accumulators
WARN I N G
Personal injury or death can result from improper accumulator charging. Dry nitrogen is
the only gas approved for use in the accumulator. Charging accumulator with oxygen gas
will cause an explosion. This danger will not happen if nitrogen cylinders with standard
CGA (Compressed Gas Association, Inc.) Number 580 connections are used. When
ordering nitrogen gas, be sure that cylinders are equipped with CGA Number 580
Connections. DO NOT use color codes or other methods of identification to tell difference
Never use an adapter to connect your nitrog n charging group to a valve outlet used on
both nitrogen, oxygen or gas cylinders. Be sure you use dry nitrogen (99.8% purity).
Sudden movement of machine or release of oil under pressure can cause serious injury to
persons on or near machine. To prevent possible injury, perform procedure that follows
before testing and adjusting hydraulic system.
Cold ambient temperaures could result in loss of secondary braking capability due to
inadequate hydraulic accumulator nitrogen pre-charge. Loss of secondary braking system
as well as main hydraulic pressure will result in little or no braking capability and a
potential for injury or death.
N OT E
It is recommended to perform a brake accumulator check anytime machine has been idle
for longer than two hours below -13°F (-25°C).
1. Park machine on hard, level surface (TM 5-3805-293-10).
2. Release hydraulic system pressure. Pump service brake pedal at intervals of one second on and one second
off for at least 110 applications.
N OT E
In order to correctly charge the accumulator, the piston in the brake accumulator must be
on the bottom of the cylinder. The air temperature outside the accumulator is the ambient
temperature. Before the dry nitrogen pressure in the accumulator can be accurately
checked, the temperature of the accumulator must be equal to the ambient temperature.
Before the accumulator may be correctly charged, the temperature of the accumulator
must be equal to the ambient temperature.